Add support for measuring and appraising the IMA policy itself.
Changelog v4:
- use braces on both if/else branches, even if single line on one of the
branches - Dmitry
- Use the id mapping - Dmitry
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Petko Manolov <petkan@mip-labs.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Add IMA policy support for measuring/appraising the kexec image and
initramfs. Two new IMA policy identifiers KEXEC_KERNEL_CHECK and
KEXEC_INITRAMFS_CHECK are defined.
Example policy rules:
measure func=KEXEC_KERNEL_CHECK
appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig
measure func=KEXEC_INITRAMFS_CHECK
appraise func=KEXEC_INITRAMFS_CHECK appraise_type=imasig
Moving the enumeration to the vfs layer simplified the patches, allowing
the IMA changes, for the most part, to be separated from the other
changes. Unfortunately, passing either a kernel_read_file_id or a
ima_hooks enumeration within IMA is messy.
Option 1: duplicate kernel_read_file enumeration in ima_hooks
enum kernel_read_file_id {
...
READING_KEXEC_IMAGE,
READING_KEXEC_INITRAMFS,
READING_MAX_ID
enum ima_hooks {
...
KEXEC_KERNEL_CHECK
KEXEC_INITRAMFS_CHECK
Option 2: define ima_hooks as extension of kernel_read_file
eg: enum ima_hooks {
FILE_CHECK = READING_MAX_ID,
MMAP_CHECK,
In order to pass both kernel_read_file_id and ima_hooks values, we
would need to specify a struct containing a union.
struct caller_id {
union {
enum ima_hooks func_id;
enum kernel_read_file_id read_id;
};
};
Option 3: incorportate the ima_hooks enumeration into kernel_read_file_id,
perhaps changing the enumeration name.
For now, duplicate the new READING_KEXEC_IMAGE/INITRAMFS in the ima_hooks.
Changelog v4:
- replaced switch statement with a kernel_read_file_id to an ima_hooks
id mapping array - Dmitry
- renamed ima_hook tokens KEXEC_CHECK and INITRAMFS_CHECK to
KEXEC_KERNEL_CHECK and KEXEC_INITRAMFS_CHECK respectively - Dave Young
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Petko Manolov <petkan@mip-labs.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Cc: Dave Young <dyoung@redhat.com>
Replace copy_module_from_fd() with kernel_read_file_from_fd().
Although none of the upstreamed LSMs define a kernel_module_from_file
hook, IMA is called, based on policy, to prevent unsigned kernel modules
from being loaded by the original kernel module syscall and to
measure/appraise signed kernel modules.
The security function security_kernel_module_from_file() was called prior
to reading a kernel module. Preventing unsigned kernel modules from being
loaded by the original kernel module syscall remains on the pre-read
kernel_read_file() security hook. Instead of reading the kernel module
twice, once for measuring/appraising and again for loading the kernel
module, the signature validation is moved to the kernel_post_read_file()
security hook.
This patch removes the security_kernel_module_from_file() hook and security
call.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
The kernel_read_file security hook is called prior to reading the file
into memory.
Changelog v4+:
- export security_kernel_read_file()
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Replace the fw_read_file_contents with kernel_file_read_from_path().
Although none of the upstreamed LSMs define a kernel_fw_from_file hook,
IMA is called by the security function to prevent unsigned firmware from
being loaded and to measure/appraise signed firmware, based on policy.
Instead of reading the firmware twice, once for measuring/appraising the
firmware and again for reading the firmware contents into memory, the
kernel_post_read_file() security hook calculates the file hash based on
the in memory file buffer. The firmware is read once.
This patch removes the LSM kernel_fw_from_file() hook and security call.
Changelog v4+:
- revert dropped buf->size assignment - reported by Sergey Senozhatsky
v3:
- remove kernel_fw_from_file hook
- use kernel_file_read_from_path() - requested by Luis
v2:
- reordered and squashed firmware patches
- fix MAX firmware size (Kees Cook)
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
This patch defines a new IMA hook ima_post_read_file() for measuring
and appraising files read by the kernel. The caller loads the file into
memory before calling this function, which calculates the hash followed by
the normal IMA policy based processing.
Changelog v5:
- fail ima_post_read_file() if either file or buf is NULL
v3:
- rename ima_hash_and_process_file() to ima_post_read_file()
v1:
- split patch
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Cleanup the function arguments by using "ima_hooks" enumerator as needed.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Petko Manolov <petkan@mip-labs.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Instead of passing pointers to pointers to ima_collect_measurent() to
read and return the 'security.ima' xattr value, this patch moves the
functionality to the calling process_measurement() to directly read
the xattr and pass only the hash algo to the ima_collect_measurement().
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).
Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This patch adds the iint associated to the current inode as a new
parameter of ima_add_violation(). The passed iint is always not NULL
if a violation is detected. This modification will be used to determine
the inode for which there is a violation.
Since the 'd' and 'd-ng' template field init() functions were detecting
a violation from the value of the iint pointer, they now check the new
field 'violation', added to the 'ima_event_data' structure.
Changelog:
- v1:
- modified an old comment (Roberto Sassu)
Signed-off-by: Roberto Sassu <rsassu@suse.de>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
__getname() uses slab allocation which is faster than kmalloc.
Make use of it.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This patch completes the switching to the 'ima_policy_flag' variable
in the checks at the beginning of IMA functions, starting with the
commit a756024e.
Checking 'iint_initialized' is completely unnecessary, because
S_IMA flag is unset if iint was not allocated. At the same time
the integrity cache is allocated with SLAB_PANIC and the kernel will
panic if the allocation fails during kernel initialization. So on
a running system iint_initialized is always true and can be removed.
Changes in v3:
* not limiting test to IMA_APPRAISE (spotted by Roberto Sassu)
Changes in v2:
* 'iint_initialized' removal patch merged to this patch (requested
by Mimi)
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Acked-by: Roberto Sassu <roberto.sassu@polito.it>
This patch fixes the detection of the 'open_writers' violation for mmaped
files.
before) an 'open_writers' violation is detected if the policy contains
a rule with the criteria: func=FILE_CHECK mask=MAY_READ
after) an 'open_writers' violation is detected if the current event
matches one of the policy rules.
With the old behaviour, the 'open_writers' violation is not detected
in the following case:
policy:
measure func=FILE_MMAP mask=MAY_EXEC
steps:
1) open a shared library for writing
2) execute a binary that links that shared library
3) during the binary execution, modify the shared library and save
the change
result:
the 'open_writers' violation measurement is not present in the IMA list.
Only binaries executed are protected from writes. For libraries mapped
in memory there is the flag MAP_DENYWRITE for this purpose, but according
to the output of 'man mmap', the mmap flag is ignored.
Since ima_rdwr_violation_check() is now called by process_measurement()
the information about if the inode must be measured is already provided
by ima_get_action(). Thus the unnecessary function ima_must_measure()
has been removed.
Changes in v3 (Dmitry Kasatkin):
- Violation for MMAP_CHECK function are verified since this patch
- Changed patch description a bit
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This patch fixes a race condition between two functions that try to access
the same inode. Since the i_mutex lock is held and released separately
in the two functions, there may be the possibility that a violation is
not correctly detected.
Suppose there are two processes, A (reader) and B (writer), if the
following sequence happens:
A: ima_rdwr_violation_check()
B: ima_rdwr_violation_check()
B: process_measurement()
B: starts writing the inode
A: process_measurement()
the ToMToU violation (a reader may be accessing a content different from
that measured, due to a concurrent modification by a writer) will not be
detected. To avoid this issue, the violation check and the measurement
must be done atomically.
This patch fixes the problem by moving the violation check inside
process_measurement() when the i_mutex lock is held. Differently from
the old code, the violation check is executed also for the MMAP_CHECK
hook (other than for FILE_CHECK). This allows to detect ToMToU violations
that are possible because shared libraries can be opened for writing
while they are in use (according to the output of 'man mmap', the mmap()
flag MAP_DENYWRITE is ignored).
Changes in v5 (Roberto Sassu):
* get iint if action is not zero
* exit process_measurement() after the violation check if action is zero
* reverse order process_measurement() exit cleanup (Mimi)
Changes in v4 (Dmitry Kasatkin):
* iint allocation is done before calling ima_rdrw_violation_check()
(Suggested-by Mimi)
* do not check for violations if the policy does not contain 'measure'
rules (done by Roberto Sassu)
Changes in v3 (Dmitry Kasatkin):
* no violation checking for MMAP_CHECK function in this patch
* remove use of filename from violation
* removes checking if ima is enabled from ima_rdrw_violation_check
* slight style change
Suggested-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This patch introduces the new variable 'ima_policy_flag', whose bits
are set depending on the action of the current policy rules. Only the
flags IMA_MEASURE, IMA_APPRAISE and IMA_AUDIT are set.
The new variable will be used to improve performance by skipping the
unnecessary execution of IMA code if the policy does not contain rules
with the above actions.
Changes in v6 (Roberto Sassu)
* do not check 'ima_initialized' before calling ima_update_policy_flag()
in ima_update_policy() (suggested by Dmitry)
* calling ima_update_policy_flag() moved to init_ima to co-locate with
ima_initialized (Dmitry)
* add/revise comments (Mimi)
Changes in v5 (Roberto Sassu)
* reset IMA_APPRAISE flag in 'ima_policy_flag' if 'ima_appraise' is set
to zero (reported by Dmitry)
* update 'ima_policy_flag' only if IMA initialization is successful
(suggested by Mimi and Dmitry)
* check 'ima_policy_flag' instead of 'ima_initialized'
(suggested by Mimi and Dmitry)
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
ima_init() is used as a single place for all initializations.
Experimental keyring patches used the 'late_initcall' which was
co-located with the late_initcall(init_ima). When the late_initcall
for the keyring initialization was abandoned, initialization moved
to init_ima, though it would be more logical to move it to ima_init,
where the rest of the initialization is done. This patch moves the
keyring initialization to ima_init() as a preparatory step for
loading the keys which will be added to ima_init() in following
patches.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
In all cases except ima_bprm_check() the filename was not defined
and ima_d_path() was used to find the full path. Unfortunately,
the bprm filename is a relative pathname (eg. ./<dir>/filename).
ima_bprm_check() selects between bprm->interp and bprm->filename.
The following dump demonstrates the differences between using
filename and interp.
bprm->filename
filename: ./foo.sh, pathname: /root/bin/foo.sh
filename: ./foo.sh, pathname: /bin/dash
bprm->interp
filename: ./foo.sh, pathname: /root/bin/foo.sh
filename: /bin/sh, pathname: /bin/dash
In both cases the pathnames are currently the same. This patch
removes usage of filename and interp in favor of d_absolute_path.
Changes v3:
- 11 extra bytes for "deleted" not needed (Mimi)
- purpose "replace relative bprm filename with full pathname" (Mimi)
Changes v2:
- use d_absolute_path() instead of d_path to work in chroot environments.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
'function' variable value can be changed instead of
allocating extra '_func' variable.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Precede bit testing before string comparison makes code
faster. Also refactor statement as a single line pointer
assignment. Logic is following: we set 'xattr_ptr' to read
xattr value when we will do appraisal or in any case when
measurement template is other than 'ima'.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Empty files and missing xattrs do not guarantee that a file was
just created. This patch passes FILE_CREATED flag to IMA to
reliably identify new files.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> 3.14+
On ima_file_free(), newly created empty files are not labeled with
an initial security.ima value, because the iversion did not change.
Commit dff6efc "fs: fix iversion handling" introduced a change in
iversion behavior. To verify this change use the shell command:
$ (exec >foo)
$ getfattr -h -e hex -d -m security foo
This patch defines the IMA_NEW_FILE flag. The flag is initially
set, when IMA detects that a new file is created, and subsequently
checked on the ima_file_free() hook to set the initial security.ima
value.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> 3.14+
The "security: introduce kernel_fw_from_file hook" patch defined a
new security hook to evaluate any loaded firmware that wasn't built
into the kernel.
This patch defines ima_fw_from_file(), which is called from the new
security hook, to measure and/or appraise the loaded firmware's
integrity.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Require all keys added to the IMA keyring be signed by an
existing trusted key on the system trusted keyring.
Changelog v6:
- remove ifdef CONFIG_IMA_TRUSTED_KEYRING in C code - Dmitry
- update Kconfig dependency and help
- select KEYS_DEBUG_PROC_KEYS - Dmitry
Changelog v5:
- Move integrity_init_keyring() to init_ima() - Dmitry
- reset keyring[id] on failure - Dmitry
Changelog v1:
- don't link IMA trusted keyring to user keyring
Changelog:
- define stub integrity_init_keyring() function (reported-by Fengguang Wu)
- differentiate between regular and trusted keyring names.
- replace printk with pr_info (D. Kasatkin)
- only make the IMA keyring a trusted keyring (reported-by D. Kastatkin)
- define stub integrity_init_keyring() definition based on
CONFIG_INTEGRITY_SIGNATURE, not CONFIG_INTEGRITY_ASYMMETRIC_KEYS.
(reported-by Jim Davis)
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Acked-by: David Howells <dhowells@redhat.com>
process_measurement() always calls ima_template_desc_current(),
including when an IMA policy has not been defined.
This patch delays template descriptor lookup until action is
determined.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Before 2.6.39 inode->i_readcount was maintained by IMA. It was not atomic
and protected using spinlock. For 2.6.39, i_readcount was converted to
atomic and maintaining was moved VFS layer. Spinlock for some unclear
reason was replaced by i_mutex.
After analyzing the code, we came to conclusion that i_mutex locking is
unnecessary, especially when an IMA policy has not been defined.
This patch removes i_mutex locking from ima_rdwr_violation_check().
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
When IMA did not support ima-appraisal, existance of the S_IMA flag
clearly indicated that the file was measured. With IMA appraisal S_IMA
flag indicates that file was measured and/or appraised. Because of
this, when measurement is not enabled by the policy, violations are
still reported.
To differentiate between measurement and appraisal policies this
patch checks the inode integrity cache flags. The IMA_MEASURED
flag indicates whether the file was actually measured, while the
IMA_MEASURE flag indicates whether the file should be measured.
Unfortunately, the IMA_MEASURED flag is reset to indicate the file
needs to be re-measured. Thus, this patch checks the IMA_MEASURE
flag.
This patch limits the false positive violation reports, but does
not fix it entirely. The IMA_MEASURE/IMA_MEASURED flags are
indications that, at some point in time, the file opened for read
was in policy, but might not be in policy now (eg. different uid).
Other changes would be needed to further limit false positive
violation reports.
Changelog:
- expanded patch description based on conversation with Roberto (Mimi)
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
ima_rdwr_violation_check is called for every file openning.
The function checks the policy even when violation condition
is not met. It causes unnecessary policy checking.
This patch does policy checking only if violation condition is met.
Changelog:
- check writecount is greater than zero (Mimi)
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Files are measured or appraised based on the IMA policy. When a
file, in policy, is opened with the O_DIRECT flag, a deadlock
occurs.
The first attempt at resolving this lockdep temporarily removed the
O_DIRECT flag and restored it, after calculating the hash. The
second attempt introduced the O_DIRECT_HAVELOCK flag. Based on this
flag, do_blockdev_direct_IO() would skip taking the i_mutex a second
time. The third attempt, by Dmitry Kasatkin, resolves the i_mutex
locking issue, by re-introducing the IMA mutex, but uncovered
another problem. Reading a file with O_DIRECT flag set, writes
directly to userspace pages. A second patch allocates a user-space
like memory. This works for all IMA hooks, except ima_file_free(),
which is called on __fput() to recalculate the file hash.
Until this last issue is addressed, do not 'collect' the
measurement for measuring, appraising, or auditing files opened
with the O_DIRECT flag set. Based on policy, permit or deny file
access. This patch defines a new IMA policy rule option named
'permit_directio'. Policy rules could be defined, based on LSM
or other criteria, to permit specific applications to open files
with the O_DIRECT flag set.
Changelog v1:
- permit or deny file access based IMA policy rules
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Cc: <stable@vger.kernel.org>
This is a small refactoring so ima_d_path() returns dentry name
if path reconstruction fails. It simplifies callers actions
and removes code duplication.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Between checkpatch changes (eg. sizeof) and inconsistencies between
Lindent and checkpatch, unfixed checkpatch errors make it difficult
to see new errors. This patch fixes them. Some lines with over 80 chars
remained unchanged to improve code readability.
The "extern" keyword is removed from internal evm.h to make it consistent
with internal ima.h.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This patch defines a new template called 'ima-sig', which includes
the file signature in the template data, in addition to the file's
digest and pathname.
A template is composed of a set of fields. Associated with each
field is an initialization and display function. This patch defines
a new template field called 'sig', the initialization function
ima_eventsig_init(), and the display function ima_show_template_sig().
This patch modifies the .field_init() function definition to include
the 'security.ima' extended attribute and length.
Changelog:
- remove unused code (Dmitry Kasatkin)
- avoid calling ima_write_template_field_data() unnecesarily (Roberto Sassu)
- rename DATA_FMT_SIG to DATA_FMT_HEX
- cleanup ima_eventsig_init() based on Roberto's comments
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
The IMA measurement list contains two hashes - a template data hash
and a filedata hash. The template data hash is committed to the TPM,
which is limited, by the TPM v1.2 specification, to 20 bytes. The
filedata hash is defined as 20 bytes as well.
Now that support for variable length measurement list templates was
added, the filedata hash is not limited to 20 bytes. This patch adds
Kconfig support for defining larger default filedata hash algorithms
and replacing the builtin default with one specified on the kernel
command line.
<uapi/linux/hash_info.h> contains a list of hash algorithms. The
Kconfig default hash algorithm is a subset of this list, but any hash
algorithm included in the list can be specified at boot, using the
'ima_hash=' kernel command line option.
Changelog v2:
- update Kconfig
Changelog:
- support hashes that are configured
- use generic HASH_ALGO_ definitions
- add Kconfig support
- hash_setup must be called only once (Dmitry)
- removed trailing whitespaces (Roberto Sassu)
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
The same hash algorithm should be used for calculating the file
data hash for the IMA measurement list, as for appraising the file
data integrity. (The appraise hash algorithm is stored in the
'security.ima' extended attribute.) The exception is when the
reference file data hash digest, stored in the extended attribute,
is larger than the one supported by the template. In this case,
the file data hash needs to be calculated twice, once for the
measurement list and, again, for appraisal.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Pass the file descriptor instead of the inode to ima_add_violation(),
to make the latter consistent with ima_store_measurement() in
preparation for the new template architecture.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
All files on the filesystem, currently, are hashed using the same hash
algorithm. In preparation for files from different packages being
signed using different hash algorithms, this patch adds support for
reading the signature hash algorithm from the 'security.ima' extended
attribute and calculates the appropriate file data hash based on it.
Changelog:
- fix scripts Lindent and checkpatch msgs - Mimi
- fix md5 support for older version, which occupied 20 bytes in the
xattr, not the expected 16 bytes. Fix the comparison to compare
only the first 16 bytes.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
In preparation of supporting more hash algorithms with larger hash sizes
needed for signature verification, this patch replaces the 20 byte sized
digest, with a more flexible structure. The new structure includes the
hash algorithm, digest size, and digest.
Changelog:
- recalculate filedata hash for the measurement list, if the signature
hash digest size is greater than 20 bytes.
- use generic HASH_ALGO_
- make ima_calc_file_hash static
- scripts lindent and checkpatch fixes
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Replace a bunch of file->dentry->d_inode refs with file_inode().
In __fput(), use file->f_inode instead so as not to be affected by any tricks
that file_inode() might grow.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Passing a pointer to the dentry name, as a parameter to
process_measurement(), causes a race condition with rename() and
is unnecessary, as the dentry name is already accessible via the
file parameter.
In the normal case, we use the full pathname as provided by
brpm->filename, bprm->interp, or ima_d_path(). Only on ima_d_path()
failure, do we fallback to using the d_name.name, which points
either to external memory or d_iname.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Pull vfs pile (part one) from Al Viro:
"Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
locking violations, etc.
The most visible changes here are death of FS_REVAL_DOT (replaced with
"has ->d_weak_revalidate()") and a new helper getting from struct file
to inode. Some bits of preparation to xattr method interface changes.
Misc patches by various people sent this cycle *and* ocfs2 fixes from
several cycles ago that should've been upstream right then.
PS: the next vfs pile will be xattr stuff."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
saner proc_get_inode() calling conventions
proc: avoid extra pde_put() in proc_fill_super()
fs: change return values from -EACCES to -EPERM
fs/exec.c: make bprm_mm_init() static
ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
ocfs2: fix possible use-after-free with AIO
ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
target: writev() on single-element vector is pointless
export kernel_write(), convert open-coded instances
fs: encode_fh: return FILEID_INVALID if invalid fid_type
kill f_vfsmnt
vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
nfsd: handle vfs_getattr errors in acl protocol
switch vfs_getattr() to struct path
default SET_PERSONALITY() in linux/elf.h
ceph: prepopulate inodes only when request is aborted
d_hash_and_lookup(): export, switch open-coded instances
9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
9p: split dropping the acls from v9fs_set_create_acl()
...
Commit "750943a ima: remove enforce checking duplication" combined
the 'in IMA policy' and 'enforcing file integrity' checks. For
the non-file, kernel module verification, a specific check for
'enforcing file integrity' was not added. This patch adds the
check.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Pull security subsystem updates from James Morris:
"This is basically a maintenance update for the TPM driver and EVM/IMA"
Fix up conflicts in lib/digsig.c and security/integrity/ima/ima_main.c
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (45 commits)
tpm/ibmvtpm: build only when IBM pseries is configured
ima: digital signature verification using asymmetric keys
ima: rename hash calculation functions
ima: use new crypto_shash API instead of old crypto_hash
ima: add policy support for file system uuid
evm: add file system uuid to EVM hmac
tpm_tis: check pnp_acpi_device return code
char/tpm/tpm_i2c_stm_st33: drop temporary variable for return value
char/tpm/tpm_i2c_stm_st33: remove dead assignment in tpm_st33_i2c_probe
char/tpm/tpm_i2c_stm_st33: Remove __devexit attribute
char/tpm/tpm_i2c_stm_st33: Don't use memcpy for one byte assignment
tpm_i2c_stm_st33: removed unused variables/code
TPM: Wait for TPM_ACCESS tpmRegValidSts to go high at startup
tpm: Fix cancellation of TPM commands (interrupt mode)
tpm: Fix cancellation of TPM commands (polling mode)
tpm: Store TPM vendor ID
TPM: Work around buggy TPMs that block during continue self test
tpm_i2c_stm_st33: fix oops when i2c client is unavailable
char/tpm: Use struct dev_pm_ops for power management
TPM: STMicroelectronics ST33 I2C BUILD STUFF
...
Different hooks can require different methods for appraising a
file's integrity. As a result, an integrity appraisal status is
cached on a per hook basis.
Only a hook specific rule, requires the inode to be re-appraised.
This patch eliminates unnecessary appraisals.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
With the new IMA policy 'appraise_type=' option, different hooks
can require different methods for appraising a file's integrity.
For example, the existing 'ima_appraise_tcb' policy defines a
generic rule, requiring all root files to be appraised, without
specfying the appraisal method. A more specific rule could require
all kernel modules, for example, to be signed.
appraise fowner=0 func=MODULE_CHECK appraise_type=imasig
appraise fowner=0
As a result, the integrity appraisal results for the same inode, but
for different hooks, could differ. This patch caches the integrity
appraisal results on a per hook basis.
Changelog v2:
- Rename ima_cache_status() to ima_set_cache_status()
- Rename and move get_appraise_status() to ima_get_cache_status()
Changelog v0:
- include IMA_APPRAISE/APPRAISED_SUBMASK in IMA_DO/DONE_MASK (Dmitry)
- Support independent MODULE_CHECK appraise status.
- fixed IMA_XXXX_APPRAISE/APPRAISED flags
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
The 'security.ima' extended attribute may contain either the file data's
hash or a digital signature. This patch adds support for requiring a
specific extended attribute type. It extends the IMA policy with a new
keyword 'appraise_type=imasig'. (Default is hash.)
Changelog v2:
- Fixed Documentation/ABI/testing/ima_policy option syntax
Changelog v1:
- Differentiate between 'required' vs. 'actual' extended attribute
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This patch forbids write access to files with digital signatures, as they
are considered immutable.
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Define a new function ima_d_path(), which returns the full pathname.
This function will be used further, for example, by the directory
verification code.
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Based on the IMA appraisal policy, files are appraised. For those
files appraised, the IMA hooks return the integrity appraisal result,
assuming IMA-appraisal is in enforcing mode. This patch combines
both of these criteria (in policy and enforcing file integrity),
removing the checking duplication.
Changelog v1:
- Update hook comments
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
